<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<select >
    <script>
        var i=1900;
        for(var i=1990;i<=2020;i++){
            document.write("<option>"+i+"</option>");
        }

    </script>
</select>
<select >
    <script>
        for(var i=1;i<=12;i++){
            document.write("<option>"+i+"</option>");
        }

    </script>
</select>
<select >
    <script>

        for(var i=1;i<=31;i++){
            document.write("<option>"+i+"</option>");
        }

    </script>
</select>
</body>
</html>